A study is proposed to explore the role of the coeruleospinal neurones in the labyrinth and neck reflexes. The electrical activity of coerulespinal neurones, antidromically identified by spinal cord stimulation, will be recorded and their activity tested during sinusoidal stimulation of labyrinth and neck receptors. Comparisons will then be made of the dynamic characteristics of responses of coeruleospinal neurones evaluated by means of the Fourier analysis with the response characteristics of vestibulospinal neurons to the same inputs.